During the period of 1989-2003, under the support from seven related programs including the 7th, 8th and 9th Five-Year key industrial R & D Programs of China's Ministry of Agriculture, and “Chinese National Programs for High Technology Research and Development Program (863 Program)” of China's Ministry of Science and Technology, key and major projects of National Natural Science Foundation of China etc., the research working on “the breeding, germplasm characteristics, as well as development and utilization of Wuzhishan inbred line” had made many breakthroughs, including but not limited to, taking a boar and a sow from Wuzhishan pigs (also referred as Wuzhishan miniature pigs) as line ancestors, continuously employing “offspring-parent”, “full sibs” mating, and other comprehensive measures, gradually overcoming the adverse effects that inbreeding resulted in very low breeding survival rate, which was less than 20% at that time, establishing F17 inbred line population and genealogy, monitoring the research process of inbred line breeding of inbred line varieties F7-F16 by using many advanced technical means, such as molecularly genetic means, DNA fingerprinting similarity factor, microsatellite etc., preliminarily revealing genetic regularity and characteristics of Wuzhishan miniature pig inbred line, and demonstrating the facticity and scientificity of the breeding process of this inbred line. Moreover, many studies on exploitation and utilization of Wuzhishan miniature pig inbred line had been completed, showing the incomparable superiority of this inbred line in serving as an ideal animal model for human disease, and consequently achieving a certain economic benefits and major social benefits. Two achievements of the researches—“Researches on germplasm characteristics as well as exploitation and utilization of Wuzhishan miniature pigs” (Achievements Appraisal of Academy of Agricultural Sciences 95, No. 075) and “Wuzhishan miniature pig inbred line breeding for experiments and molecule genetic basic research” passed the Science and Technology Achievement Appraisals hosted by China's Ministry of Agriculture in 1995 and 2005 respectively, and won the Third Prize of China's Ministry of Agriculture Science and Technology Progress Award in 1999.
Preliminary research achievements of miniature pig inbred breeding had great influences at home and abroad. For example, industrial specialists from the United States, Italy, Japan, West Germany, Korea, and other countries had proposed for introduction and cultivation, and or cooperative study. An institute of the United States proposed to purchase 50 boars with 5 million USD in 1996; Korea proposed to cooperatively set up factories in China by funding 5 million RMB in 2000 after its introduction and cultivation proposal was rejected. The main reason behind the influences is that the inbred line animals, as special genetic resources for animals, can rapidly obtain scientific data for life science researches with the same extent of sensitivity and accuracy as from analytical reagents in chemistry and precise instruments in physics. With their very high use value and research significance, more than 450 inbred lines of mice, rats, and small mammals etc, have been bred in the world at present, and widely used as animal models for studying difficult and complicated human diseases, solving difficult problems in bioscience, medical science, and pharmaceutics, and other research fields. Due to the various differences between pigs and those small animals in interspecific physiology, the breeding of inbred line pigs has been very difficult. It was verified by novelty searching (2013. 11) that there was no successful report in the world. Moreover, compared with rodents, pigs possesses greater similarity with human, and will play irreplaceable, unique roles in the researches for studying difficult and complicated human diseases and solving difficult problems in bioscience, medical science, and pharmaceutics. Inbred line pigs are rare, valuable genetic resources of large animals in the world. Previously, in 1960s, many departments of the United States and Europe carried out the breeding research of inbred line pigs, but failed with the highest inbreeding coefficient no more than 0.75. After a 15-year breeding research, China has obtained F17 with the special Chinese miniature pig resource, and the inbreeding coefficient is up to 0.965, and more encouragingly the high incidence stage of piglet death due to inbred breeding has been overcome. Therefore, the successful breeding of inbred line pigs will be likely achieved in China firstly. After a further work in current years, Wuzhishan miniature pig inbred lines F17 to F22 have been obtained.
Because there was no successful breeding report for inbred line pigs in the world yet, and either the standard of establishment or identification method of inbred line pigs does not exist, either, we strictly referred to and followed the breeding method of inbred line mouse or rat, that was, inbreeding more than 20 generations from two pigs in same ancestor and establishing complete genealogy, testing the genetic stability thereof, establishing identification method, establishing line standard, specially on interspecific differences from current Hainan Wuzhishan pigs. Only in this way, scientific and credible evidence can be provided to the industry and the world, and such novel innovation project of genetic resource can be accomplished, thereby to benefit human beings.
Once the miniature pig inbred line is successfully bred, China will possess the proprietary intellectual property rights and the international leading level of innovative genetic germplasm resource of pig, which will fill up research blank within this research field in the world, and enrich theory and practice of inbred line breeding for large animals. Meanwhile, as an ideal “animal models” for human beings, inbred line pig is an important foundation and innovation basis for the progress of biotechnological research, which will significantly promote collaborative development and innovation in bioscience, human medical science, and pharmacy, etc. in China, and play irreplaceable position for studying difficult and complicated human diseases, extending lives, so as to benefit human beings. Therefore, it possesses important practical and theoretical significance.